Hinge fitting for adjusting the inclination of the back rest of a seat, especially of a motor vehicle



A (NB 3 E E L C I H E V R O T O M A F 0 April 25, 1967 w. STRIEN ETALHINGE FITTING FOR ADJUSTING THE INCLINATION OF TH REST OF A SEAT,ESPECIALLY 12, 1963 8 Sheets-Sheet 1 Filed Dec.

Jnvenfor:

A ril 25, 1967 w. STRIEN ETAL 3,315,298

HINGE FITTING FOR ADJUSTING THE INCLINATION OF THE BACK REST OF A SEAT,ESPECIALLY OF A MOTOR VEHICLE 8 Sheets-Sheet 2 Filed Dec. 12, 1963 Apr5, 7 w. STRIEN ETAL 3,315,298

HINGE FITTING FOR ADJUSTING THE INCLINATION OF THE BACK REST OF A SEATESPECIALLY OF A MOTOR VEHICLE Filed Dec. 12, 1963 8 Sheets-Sheet 3Juvenlars April 25, 1967 w. STRIEN ETAL 3,315,293

HINGE FITTING FOR ADJUSTING THE INCLINATION OF THE BACK REST OF A SEAT,ESPECIALLY OF A MOTOR VEHICLE 8 Sheets-Sheet 4 Filed Dec. 12, 1965 8 5 9MW 2 M K B 4 s 3B mw 3 E e h S 8 pr 1967 w. STRIEN ETAL HINGE FITTINGFDR ADJUSTING THE INCLINATION OF TH REST OF A SEAT, ESPECIALLY OF AMOTOR VEHICLE Filed Dec. 12, 1963 Jnvenfor Aprll 25, 1967 w. STRIEN ETAL3,315,293

' HINGE FITTING FOR ADJUSTING THE INCLINATION OF THE BACK REST OF ASEAT, ESPECIALLY DP A MOTOR VEHICLE Filed Dec. 12, 1965 s Sheets-Sheet 6A ril 25, 1967 w. STRIEN ETAL 3,315,293

HINGE FITTING FOR ADJUSTING THE INCLINATION OF THE BACK REST OF A SEAT,ESPECIALLY OF A MOTOR VEHICLE Filed Dec. 12, 1963 8 Sheets-Sheet 7 April25, 1967 w. STRIEN ETAL 3,315,298

HINGE FITTING FOR ADJUSTING THE INCLINATION OF THE BACK 7 REST OF ASEAT, ESPECIALLY OF A MOTOR VEHICLE Filed Dec. 12, 1963 8 Sheets-$heet 8I /OZ 1 58 l I 775 15? a 755 I i I 54 United States Patent Gfifice3,315,298 PatentedjApr. 25, 1967 3,315,298 HINGE FITTING FOR ADJUSTINGTHE INCLINA- TION OF THE BACK REST OF A SEAT, ESPE- CIALLY OF A MOTORVEHICLE Werner Strien, Fehrheilinerstrasse 39, Stuttgart-Weilimdorf,Germany; .Itirg Resag, Epplestrasse 39-A, Stuttgart-Degerloch, Germany;Wolfgang Fussnegger, Neue Ramtelstrasse 125, Leonberg-Eltingen, Germany;Volker Schmerreim, Markelstrasse 17, Stuttgart, Germany; and Sylvestervon Sass, Lindenmannstrasse 20, C- logue-Gartenstadt-Nord, Germany FiledDec. 12, 1963, Ser. No. 330,200 Claims priority, application Germany,Aug. 16, 1963, R 35,916 18 Claims. (Cl. 16-146) The present inventionrelates to a hinge fitting for adjusting the inclination of the backrest of a seat, especially of a motor vehicle, wherein a pair of suchhinge fittings are mounted on both sides of the seat and each hingefitting consists of two hinge members, one of which is associated withthe frame of the seat and the other with the back rest, and both hingemembers are pivotably connected to each other in a manner so that thehinge members of both fittings are pivota-ble about a common axis. Inorder to prevent the description of the invention from being too prolix,only one hinge fitting will hereafter be described, namely, that hingefitting which is provided with special means for adjusting the angularposition of the back rest which are not required on the other hingefitting.

The principal objects of the present invention are to provide a hingefitting which permits the inclination of the back rest of a seat to beinfinitely varied, to permit such adjustments of the back rest to becarried out very easily and quickly, to design the hinge fitting so asto take up very little space and to permit the back rest to be adjustedWithin a large angular range. The present invention includes, however,also the concept that the infinitely adjustable means may be employedonly for a fine adjustment of the back rest and that additional meansmay be provided for effecting a coarse adjustment.

It is another object of the invention to provide a hinge fitting onehinge member of which is provided with helical control means which aremounted so as to be rotatable about an axis extending parallel tothehinge axis, while the other hinge member is provided with fixedoperating means which are operatively associated with the helicalcontrol means, and wherein the helical control means are adapted whenbeing turned to move the operating means along a circular path about thehinge axis. It therefore the helical control means are rotatably mountedon the hinge member which is associated with the seat frame and they arerotated, the inclination of the back rest will be changed by theoperating means which in this case are rigidly connected to the backrest.

A further object of the invention consists in designing the helicalcontrol means and the operating means which are associated therewith insuch a manner that the back rest cannot move of its own accord relativeto the seat when a force is unintentionally exerted upon the back rest,for example, by an impact upon the latter. This object may be attainedby two different arrangements. According to one of these arrangements,the helical control means and the associated operating means aredesigned so as to be in self-locking engagement with each other, forexample, like a self-locking screw connection. The term self-locking asused herein means in connection with the helical control means that atany point of the helix the pitch angle thereof which is formed, on theone hand, by the tangent applied on the helix and, on the other hand, bythe line which extends perpendicular to the radius vector which isassociated with this tangent, is smaller than the angle of frictionwhich is the arc tangent of the friction factor of the operativelyassociated parts, that is, of the helical control means and theoperating means.

A further object of the invention is to design the helical control meanspreferably in accordance with a logarithmic spiral, although it is alsopossible to design these means in accordance with a spiral of adifferent shape.

These and further features and advantages of the present invention willbecome more clearly apparent from the following detailed descriptionthereof which is to be read with reference to the accompanying drawings,in which- FIGURE 1 shows .a side view of a hinge fitting according to afirst embodiment of the invention in which the upper hinge member is ina position corresponding substantially to the upright position of theback rest;

FIGURE 2 shows a partly exploded cross section which is taken along lineIIII of FIGURE 1;

FIGURES 3 and 4 show side views of the hinge fitting according to FIGURE1 with the upper hinge member in two diiierent angular positions;

FIGURE 5 shows a side view of a hinge fitting acc0rding to amodification of the invention;

FIGURE 6 shows a side view of the upper hinge member of the hingefitting according to FIGURE 5 which carries the projections;

FIGURE 7 shows the helical guide element;

FIGURE 8 shows an enlarged partial cross section which is taken alongthe line VII-VII of FIGURE 5;

FIGURE 9 shows a partial cross section which is taken along the lineIXIX of FIGURE 5;

FIGURE 10 shows a side view of a hinge fitting according to a furthermodification of the invention from which a few parts which are notessential to the description are omitted;

FIGURE 11 shows another side view of the hinge fitting according toFIGURE 10, but with the back rest in a different angular position; and

FIGURE 12 shows an enlarged cross section which is taken along the lineXIIXII in FIGURE 10.

Referring first to FIGURES 1 to 4 of the drawings, the hinge fittingaccording to the first embodiment of the invention comprises a lowerhinge member 10 which is associated with a seat, for example, of a car,and an upper hinge member 11 which is associated with the back rest. Onthe lower hinge member 10 a journal 12 is secured which forms the swivelaxis of the back rest and on which the upper hinge member 11 isrotatably mounted. In order to prevent the upper hinge member fromsliding in the axial direction on the journal 12, it is locked thereonby a screw 13 which is screwed into the internal thread of the tubularjournal 12.

The lower hinge member 10 consists of an inner shell 14- with acylindrical rim 15 and an outer shell 16 which likewise has acylindrical rim 17. In the assembled condition, the inner and outershells together form a housing and the rim 17 overlaps the rim 15. Boththe inner and outer shells 14 and 16 have a bushing 18 or 19,respectively, for receiving a shaft 21 which is nonrotatably connectedto a disk 20 and extends parallel to the journal 12. Disk 20 carries ahelically shaped channel member 22 the riblike arms of which extend atright angles to the side of disk 20 facing the upper hinge member 11. Asshown in FIGURE 2, channel 22 has a U-shaped cross section. Shaft 21extends through an arcuate aperture 36 in the upper hinge member 11which extends coaxially to the swivel axis of the back rest and isrigidly connected to a knob 25 by means of a square head 23 and a screw24. Knob 25 and screw 24 are not shown in FIGURES 1, 3, and 4 for thesake of clarity of the illustration.

The upper hinge member 11 carries a segment 26 which is coaxial to theswivel axis of the back rest and carries three cylindrical projections27, 28, and 29 which are equally spaced from each other and are alsoequally spaced radially from the swivel axis of the back rest. Thedistance between each pair of adjacent projections 27 and 28 or 28 and29 is equal to the pitch of the helical guide 22. These projectionsextend through an arcuate aperture 31, which is coaxial to the swivelaxis of the back rest and provided in the outer shell 16 of the lowerhinge member 10, and then into the space between the inner and outershells 14 and 16 of the lower hinge member 10, and they are provided forengaging into the channel 22 the lateral inner walls of which extendparallel to each other in a helical direction. The axes of the twospirals coincide with the axis of shaft 21. Generally only one of theprojections 27 to 29-in FIGURE 1 it is the projection 27-is inengagement with the channel 22.

If disk 20 and thus the channel 22 is turned by hand, for example, inthe counterclockwise direction according to FIGURE 1 by means of theknob 25, the projection 27 which then engages into the channel 22 willmove in the clockwise direction along a circle around the swivel axis ofthe back rest. Since the projection 27 is secured to the upper hingemember 11, the latter will then likewise be turned in the clockwisedirection about the swivel axis of the back rest. When channel 22 isfurther turned, it finally reaches a position as shown in FIGURE 3, inwhich the projection 27 engages with the outer end of channel 22, whilethe next projection 28 has entered the inner end of channel 22. Whenchannel 22 is still further turned, the projection 27 leaves the channel22 and the positive transmission of the adjusting movement is continuedby the projection 28.

As illustrated in FIGURES 1, 3, and 4, the helical channel 22 preferablyextends approximately for an angular distance greater than 360 by suchan angle as is formed by two radial vectors of the spiral which encloseone projection. It is therefore evident that there will always be apositive engagement between the projection and the helical channel sinceone projection always enters the channel at one end before the precedingprojection leaves the channel at the other end.

The size of the pitch of the helical guide channel is limited upwardlydue to the fact that the unit consisting of the channel and theprojections should have a selflocking action. This applies if the leadangle is smaller than the angle of friction. The lead angle a is thatangle which, as shown in FIGURE 1, is formed at any point of the spiralbetween the normal line N intersecting at a point P on the spiral atright angles to a vector L and the tangent T of this point ofintersection P. The

angle of friction is the arc tangent of the friction factor.

The pitch of the helical guide channel may be increased if theprojections and the channel are made of materials which have a highfriction factor. Since it is desirable to be able to pass through theentire range of adjustment of the back rest with as few revolutions ofdisk 20 as possible, the channel is preferably made in the form of alogarithmic spiral since the lead angle is identical at any point ofsuch a spiral so that the available angle of friction in the helicalguide channel can always by fully utilized. It is, however, alsopossible to employ a different kind of spiral for example, anArchimedean spiral.

Since the lead angle of the helical channel depends upon the frictionfactor, a large range of adjustment would mean that the channel wouldhave to be very long if only one projection is used. This would alsorequire the entire hinge fitting to be very large and larger than thespace which is usually available for it. It is therefore advisable asshown in the drawings to provide three projections which permit thehelical guide channel to be made of only one third of the length whichwould be required if only one projection were provided.

Disk 20 may be additionally locked against any undesired adjustment bymeans of a resilient element 32, as shown in FIGURE 2, which pressesupon the rear side of disk 20. For the same purpose it is also possibleto make the bushings 18 and 19 as well as the shaft 21 of materials witha high friction factor.

In order to facilitate the operation of raising the back rest, for whichpurpose it is necessary to turn the disk 20 in the clockwise direction,as seen in FIGURES 3 and 4, it is also possible to provide 'aconventional return spring which balances the weight of the back rest.

For holding the two sides of the back rest, which should be of anondistortable construction, parallel to each other in any angularposition, it is only necessary to connect the hinge members 11 of bothhinge fittings rigidly to each other, for example, by means of aconnecting rod 34, as shown in FIGURE 3. The equal movement of these twohinge members 11 may be attained by rigidly connecting the square ends33 on the inner ends of the shafts 21 of the two fittings with eachother.

Instead of having a round cross section as illustrated, the projections27, 28, and 29 may 'also be made of a shape which complies as much aspossible with the curvature of the helical channel, so that the forceswill not be transmitted from one part to the other by mere points orlines of engagement but by a contact between surfaces.

The hinge members 10 and 11 which are pivotably connected to each otherhave to be provided at both sides of 'a seat, whereas the helical guidechannel is required only at one side.

FIGURES 5 to 9 illustrate a hinge fitting according to a modification ofthe invention. This hinge fitting comprises a hinge member 202 which isrigidly connected to the back rest 201, and a hinge member 204 which ispivotably connected to the first hinge member 202 by means of a joint203 and to the seat frame 205 by a pivot in the form of a bolt 206. Itis further supported in a conventional manner, not particularly shown,on a point of the seat frame 205, for example, 'at 207, which is spacedfrom bolt 206. On the other side of the seat 208, a similar pair ofhinge members is mounted in the corresponding position and the hingemembers 202 of the two hinge fittings which support the back rest arerigidly connected to each other, for example, by a pipe 209 of a squarecross section. As shown particularly in FIGURE 9, joint 203 comprises athreaded bolt 210 which is screwed into a nut 211 and has a shoulder210'. Between nut 211 and shoulder 210' a washer 212 is inserted whichhas a larger diameter than this nut and shoulder. Bolt 210 and nut 211carry the hinge members 202 and 204, respectively, which are heldthereon by a head 210" on the bolt and a flange 211 on the nut.

The helical guide means as subsequently described are provided on atleast one side of the car seat.

The hinge member 204 has rigidly thereon a pin 213 which extendsparallel to the axis of the joint 203 and carries a bushing 214 to whicha disk 215 is secured the rim of which projecting at a right anglethereto forms a riblike cam member 216 which faces the two hinge membersand has the shape of a spiral the ends 216 and 216 of which areconnected by a straight rib portion. Disk 215 is rigidly connected to acaplike head 217 which covers the pin 213 and serves as a knob forturning the riblike cam member 216 about the axis of pin 213 whichcoincides with the axis of the spiral.

This riblike cam member 216 has an inner peripheral helical surface 216aand parallel thereto an outer peripheral helical surface 216]). Theinner helical surface 216a engages with a knoblike projection 218 whichis secured to the hinge member 202 and may have a shape of a sphericalor cylindrical segment. The outer helical surface 216!) engages with asecond projection 219 which consists of a block'220 or the like which isrigidly secured to the hinge member 202 and to which, in turn, a socket221 of sheet metal or the like is secured which grips one side of anelastic cushion 222, for example, of rubber, while the other side of thecushion is gripped by a similar socket 223 which engages upon the outerhelical surface 216b of the cam member 216.

When the riblike cam member 216 with its helical outer surfaces 216a and216]) is turned in one or the other direction by means of the knob 217,the projections 218 and 219 which engage with these surfaces, and thusalso the hinge member 202 which is rigidly connected to these parts 218and 219 will be swiveled in the corresponding direction about the axisof the joint 203. Small geometric inaccuracies of the constructioninsofar as the engagement of the projections 218 and 219 with the cammember 216 is concerned are compensated by the resilience of the cushion222 In order to prevent the disk 215 carrying the riblike cam member 216from turning of its own accord, a ring 224' which preferably consists ofplastic is fitted into an annular groove 224 in pin 213 in such a manneras to exert a brake action upon the bushing 214.

For effecting a coarse adjustment of the inclination of the back restwithout employng the helical guide member, the bushing 214 which carriesthe disk 215 with the helical riblike cam member 216 thereon may beshifted axially along pin 213 against the action of a spring 225 bypulling the knob 217 outwardly until the bushing 214 engages upon awasher 225' on the end of pin 213 and the cam member 216 will bedisengaged from the projections 218 and 219. After the back rest 201 hasbeen pivoted roughly to a position near the desired angle without beingguided by the helical cam member 216, the latter after beingappropriately turned may again be engaged with the projections 218 and219, whereupon a fine adjustment of the angle of the back rest may becarried out in the manner as previously described.

FIGURES to 12 illustrate a further embodiment of the invention in whichthe hinge fitting comprises a hinge member 102 which supports the backrest 101 and a hinge member 104 which is pivotably connected to thehinge member 102 by a joint 103 and also to the seat frame 105 carryingthe seat 108 by a pivot in the form of a bolt 106. Hinge member 104which is pivotable about the axis of bolt 106 rests in a conventionalmanner, not specifically shown, on the seat frame 105 at another point,for example, at 107. The same arrangement of elements is provided on theother side of the seat, and the two hinge members 102 at the two sidesof the back rest are rigidly connected to each other by a rod 109 or thelike.

The helical guide element as hereafter described is provided at least atone side of the seat.

The hinge member 104 carries a journal 113 which is mounted thereon soas to be rotatable but not movable in the axial direction by beingprovided on its end with two washers 126 and 127 which are mounted atthe opposite sides of the hinge member 104 and one of which, the washer126, is held in place on the end of journal 113 by a spring ring 128 orthe like, while the other washer 127 is held in place by a shoulder 129on journal 113. This shoulder is formed by the end of the central part113 of journal 113 which is made of a square cross section. This squarecentral part 113' carries a pair of disks 116a and 1161) and a controlknob 117 which is rigidly secured on journal 113 by another spring ring130.

Each of the two disks 116a and 11612 is provided with a helicalperipheral surface 116a or 1161:, respectively, each of which has apitch which is directed inversely to that of the peripheral surface ofthe other disk. The ends 1160 and 116' of the spiral of disk 116a andthe ends 1161)" and 116" of the spiral of disk 116b are respectivelyconnected by a peripheral part which substantially extends in thedirection of a radius vector. The helical peripheral surfaces 116a and1161) may have a shape of an Archimedean or logarithmic or othersuitable spiral.

Each helical surface 116a and 1161) engages with a .propection 118 or119, respectively, at least one of which,

6 in the present case the projection 119, is provided with an elasticcushion 122 which directly engages upon the associated helical surfaces116b.

The two projections 118 and 119 are formed by the ends of a bifurcatedarm of a two-armed lever in the form of a plate 115 which is pivotablymounted on the pivot pin of the joint 103, on which pin also the hingemembers 102 and 104 are mounted at the opposite sides of plate 115.Washers 112 are inserted between the two hinge members 102 and 104 andthe disk 115, and all rotatable parts on pivot pin 110 are locatedbetween the head 110' of this pin and a washer 131. Pivot pin 110 isdesigned in a conventional manner so as to permit the parts to be easilyslipped thereon.

The second arm of the lever as formed by plate 115 Which is pivota bleabout the pivot pin 110 of joint 103 has a plurality of bores 115' whichare located on an are about the axis of joint 103 and through either ofwhich a pin 132 may be inserted which also passes through a bore 133 inthe hinge member 102 and is provided with a control knob 134. Pin 132may be withdrawn from the respective bore 115 in which it is locatedagainst the action of a spring 136 which is held in a socket 135 whichis secured to the hinge member 102 and in which spring 136 acts at oneend upon the end flange of the socket and at the other end upon a springring 137 which is inserted into an annular groove in pin 132. When bymeans of the knob 134 pin 132 is fully Withdrawn from the mentioned bore115' in plate 115 against the action of spring 136, hinge member 102 onthe back rest may be swiveled about the joint 103 so far that pi 132will snap into another bore 115' in disk 115. It is thus possible toeffect a coarse adjustment of the inclination of the back rest 101.Intermediate the positions of the back rest which are determined by thebores 115' it is possible to effect a fine adjustment of the inclinationof the back rest by turning the knob 117 in one or the other directionand by thereby turning the disks 116a and 1161) with the helical camsurfaces 116a and 116k, whereby the projections 118 and 119/122 whichengage with these cam surfaces and therefore also the plate 115 and theback rest 101 are swiveled which is rigidly secured to this plate by thepin 132. The points of contact of the projections 118 and 119/ 122 withthe associated cam surfaces 116a' and 116b, respectively, are locatedapproximately on an are which is drawn about the axis of rotation ofplate 115, that is, the axis of the joint 103, and which extends atleast approximately through the spiral axis, i.e. the axis of pin 110.The entire hinge fitting with the exception of the control knobs 117 and134 is covered toward the outside cover plates 138 and 139.

Although our invention has been illustrated and described with referenceto the preferred embodiments thereof, We wish to have it understood thatit is in no way limited to the detials of such embodiments, but iscapable of numerous modifications within the scope of theappendedclaims.

We claim:

1. A hinge fitting for adjusting the inclination of the back rest of aseat, especially of a motor vehicle, comprising a pair of hinge membersassociated with the seat frame and with the back rest, respectively, andadapted to be pivoted relative to each other about a hinge axis, ahelical cam member consisting of a disk rotatably mounted on one of saidhinge members and having a first rib mounted on and projecting at rightangles from one of its surfaces, at least the outer peripheral surfaceof said first rib having a helical shape, the axis of rotation of saiddisk and the axis of said rib coinciding with each other and extendingparallel to said hinge axis, means nonrotatably connected to said cammember for turning the same about said disk axis, at least oneprojection secured to the other hinge member and adapted to slide alongsaid outer peripheral helical surface of said first rib, and means formaintaining said projection in engagement with said helical surface,said last means comprising a second rib mounted on and projecting atright angles from said disk, at least the inner peripheral surface ofsaid second rib having a helical shape and extending parallel to theouter periphery of said first rib and spaced therefrom at a distancesubstantially equal to the thickness of said projection and facing saidouter periphery of said first rib so that said two ribs together withsaid disk form a helical channel in which at least one projection isguided.

2. A hinge fitting as defined in claim 1, in which a plurality of saidprojections are secured to said other hinge member and are disposed onan are about said hinge axis and each spaced from the other at adistance equal to the size of the pitch of said helical channel, saidchannel having an arcuate length greater than 360 substantially by anangle formedby two radial vectors of said channel enclosing oneprojection.

3. A hinge fitting as defined in claim 1, in which said projectionengages into said channel so as to be selflocking therein.

4. A hinge fitting for adjusting the inclination of the back rest of aseat, especially of a motor vehicle, comprising a pair of hinge membersassociated with the seat frame and with the back rest, respectively, afirst axle member for pivotably connecting the two hinge members to eachother, one of said hinge members consisting of two shells having theirinner sides facing each other and removably connected to each other soas to form a housing, a second axle member mounted in said shells ofsaid housing parallel to said first axle member and having one endextending through an arcuate slot in the other hinge member extendingarcuately about said first axle member, means for turning said secondaxle member and secured to the end of said second axle member projectingthrough the other hinge member, a disk non-rotatably secured to saidsecond axle member within said housing and having an arcuate channelwith the open side thereof facing the other hinge member, the axis ofsaid helical channel coinciding with the axis of said second axlemember, at least one projection secured to the other hinge member andextending through an arcuate slot extending arcuately about the axis ofsaid first axle member and provided in the shell of the first hingemember adjacent to the other hinge member, said projection engaging intosaid channel and adapted, when said second axle member is being turnedtogether with said disk and said channel, to slide along said channelwhile being guided by said ribs forming said channel.

5. A hinge fitting for adjusting the inclination of the back rest of aseat, especially of a motor vehicle, comprising a pair of hinge membersassociated with the seat frame and with the back rest, respectively, andadapted to be pivoted relative to each other about a hinge axis, a diskrotatably mounted on one of said hinge members so as to be rotatableabout an axis parallel to said hinge axis, said disk having a helicalrib of an equal thickness at all points thereof and projecting at rightangles from said disk, the axis of said helical rib coinciding with saidaxis of said disk, means non-rotatably connected to said disk forturning the same, two projections connected to the other hinge membersubstantially on a radius vector of said helical rib and at such adistance from each other that, when said hinge members are pivotedrelative to each other about said hinge axis upon turning of said disk,said rib can slide between said projections with only a slight playbetween said projections and said rib.

6. A hinge fitting as defined in claim 5, in which the ends of saidhelical rib are connected to each other by a nonhelical rib portion sothat said rib forms a closed cam member. t I

7. A hinge fitting -as defined in claim 5, in which said disk isslidable along its-axis extending parallel to said hinge axis so as todisengage said rib from said projections.

8. A hinge fitting for adjusting the inclination of the back rest of aseat, especially of a motor vehicle, comprising a pair of hinge membersassociated with the seat frame and with the back rest, respectively, afirst axle member for pivotally connecting the two hinge members to eachother, a second axle member having one end secured to one of said hingemembers parallel to said first axle member, a bushing rotatable on andslidable axially along said second axle member, a disk rigidly connectedto said bushing and having a helical rib of an equal thickness at allpoints thereof and projecting at right angles from said disk, twoprojections connected to the other hinge member substantially on aradius vector of said helical rib and at such a distance from each otherthat, when said hinge members are pivoted relative to each other aboutsaid first axle member upon turning of said disc, said rib can slidebetween said projections with only a slight play between saidprojections and said rib, a cap-like control knob rigidly connected tosaid disk and covering said second axle member for turning said disk andsaid bushing and sliding the same in the axial direction, a washersecured to the free end of said second axle member, and a compressionspring mounted between said disk and said washer and adapted to maintainsaid rib in engagement with said projections.

9. A hinge fitting as defined in claim 8, in which said second axlemember has an annular groove, and a brake ring fitted into said grooveand projecting beyond the periphery of said second axle member andadapted to exert a brake effect upon said bushing.

'10. A hinge fitting for adjusting the inclination of the back rest of aseat, especially of a motor vehicle, comprising a pair of hinge membersassociated with the seat frame and with the back rest, respectively, andadapted to be pivoted relative to each other about a hinge axis, a pairof disks each having a helical peripheral surface of a pitch inverse tothe pitch of the peripheral surface of the other disk, said disks beingnonrotatably connected to each other and together rotatably mounted onone of said hinge members so as to be rotatable about a common axisextending parallel to said hinge axis, means nonrotatably connected tosaid disks for turning the same, two projections connected to the otherhinge member and located substantially on an are about said hinge axisand each associated with one of said disks and together adapted toembrace said disks in such a manner that, when said hinge members arepivoted relative to each other about said hinge axis, only a slight playwill exist between said projections and the peripheral surfaces of saiddisks.

11. A hinge fitting as defined in claim 10, in which the ends of thehelical peripheral surface of each of said disks are connected to eachother by a peripheral part extending radially to the axis of said disk.

12. A hinge fitting as defined in claim 10, further comprising a shaftrotatably mounted on said one of said hinge members and extendingparallel to said hinge axis, and said means including a control knob,the part of said shaft projecting from said hinge member having a squarecross section, said helical disks and said control knob being mounted onsaid square part.

13. A hinge fitting for adjusting the inclination of the back rest of aseat, especially of a motor vehicle, comprising a pair of hinge membersassociated with the seat frame and with the back rest, respectively, afirst axle member for pivotably connecting said hinge members to eachother, a pair of disks having helical peripheral surfaces each having apitch inverse to the pitch of the helical surface of the other disk,said disks being nonrotatably connected to each other and togetherrotatably mounted on one of said hinge members so as to be rotatableabout a common axis extending parallel to said first axle member, meansnonrotatably connected to said disks for turning the same, a platerotatably mounted on said first axle member so as to form a two-armedlever one arm of said lever being bifurcated and the two ends of saidarm forming projections disposed substantially on an arc around the axisof said first axle member and each adapted to engage with the helicalperipheral surface of one of said disks and together adapted to embracesaid disks in such a manner that when said hinge members are pivotedrelative to each other about the axis of said first axle member uponturning of said discs, only a slight play will exist between saidprojections and said disks, the other arm of said lever being adapted tobe selectively connected to the other hinge member in different angularpositions of said hinge members relative to each other.

14. A hinge fitting for adjusting the inclination of the back rest of aseat, especially of a motor vehicle, comprising a pair of hinge membersassociated with the seat frame and with the back rest, respectively, andpivotally connected to each other so as to be pivotal relative to eachother about a hinge axis, a helical cam member consisting of a diskrotatably mounted on one of said hinge members and having a rib mountedon and projecting at right angles from one of its surfaces, at least theouter peripheral surface of said rib having a helical shape, the axis ofrotation of said disk and the axis of said rib coinciding with eachother and extending parallel to said hinge axis, means nonrotatablyconnected to said cam member for turning the same about the disk axis,at least one projection secured to the other hinge member and adapted toslide along said outer peripheral helical surface of said rib, and meansfor maintaining said projection in engagement with said helical surface.

15. A hinge fitting as defined in claim 14, in which said helical ribhas such a pitch that at any point of the helical surface thereof thelead angle formed by the tangent applied on said surface and by a lineextending at a right angle to the radius vector is smaller than the arctangent of the friction factor.

16. A hinge fitting as defined in claim 14, in which said helicalsurface of said rib has a shape of a logarithmic spiral.

17. A hinge fitting for adjusting the inclination of the back rest of aseat, especially of a motor vehicle, comprising a pair of hinge membersassociated with the seat frame and with the back rest, respectively, andadapted to be pivoted relative to each other about a hinge axis, ahelical cam member consisting of a disk rotatably mounted on one of saidhinge members so as to be rotatable about its axis extending parallel tosaid hinge axis, said disk having a rib mounted on and projecting atright angles from one of its surfaces, said rib having two parallelhelical peripheral surfaces, means nonrotatably connected to said cammember for rotating the same about said common axis, and two projectionsconnected to the other hinge member and each associated with and adaptedto slide along one of said helical surfaces respectively, said twoprojections being adapted substantially to engage with said helicalsurfaces so that, when said hinge members are pivoted relative to eachother about said hinge axis, there is only a slight play between saidprojections and said helical surfaces.

18. A hinge fitting as defined in claim 17, in which one of saidprojections at least partly consists of an elastic material.

References Cited by the Examiner UNITED STATES PATENTS 696,756 4/ '1902Rundquist 74-527 X 2,197,284 4/ 1940 Wooster 74-527 3,099,485 7/1963Beierbach et al.

FOREIGN PATENTS 42,252 3/ 1933 France. 751,894 4/ 1952 Germany. 501,62011/1954 Italy.

MARVIN A. CHAMPION, Primary Examiner. RICHARD E. MOORE, Examiner.

14. A HINGE FITTING FOR ADJUSTING THE INCLINATION OF THE BACK REST OF ASEAT, ESPECIALLY OF A MOTOR VEHICLE, COMPRISING A PAIR OF HINGE MEMBERSASSOCIATED WITH THE SEAT FRAME AND WITH THE BACK REST, RESPECTIVELY, ANDPIVOTALLY CONNECTED TO EACH OTHER SO AS TO BE PIVOTAL RELATIVE TO EACHOTHER ABOUT A HINGE AXIS, A HELICAWL CAM MEMBER CONSISTING OF A DISKROTATABLY MOUNTED ON ONE OF SAID HINGE MEMBERS AND HAVING A RIB MOUNTEDON AND PROJECTING AT RIGHT ANGLES FROM ONE OF ITS SURFACES, AT LEAST THEOUTER PERIPHERAL SURFACE OF SAID RIB HAVING A HELICAL SHAPE, THE AXIS OFROTATTION OF SAID DISK AND THE AXIS OF SAID RIB COINCIDING WITH EACHOTHER AND EXTENDING PARALLEL TO SAID HINGE AXIS, MEANS NONROTATABLYCONNECTD TO SAID CAM MEMBER FOR TURNING THE SAME ABOUT THE DISK AXIS, ATLEAST ONE PROJECTION SECURED TO THE OTHER HINGE MEMBER AND ADAPTED TOSLIDE ALONG SAID OUTER PERIPHERAL HELICAL SURFACE OF SAID RIB, AND MEANSFOR MAINTAINING SAID PROJECTION IN ENGAGEMENT WITH SAID HELICAL SURFACE.